This patent application is related to U.S. patent application Ser. No. 09/113,700 (hereinafter the xe2x80x9c""700 applicationxe2x80x9d), entitled xe2x80x9cApparatus and Method for Delivering Radiation Energy,xe2x80x9d filed on Jul. 10, 1998. The entirety of the ""700 application is herein incorporated by reference.
Described in the ""700 application is an apparatus and method for accurately positioning an array of fibers in space so that a free beam of radiation may reproducibly be directed to each fiber in the array. It has been discovered that a number of external factors can contribute to misalignment of the fibers with the free beam of radiation notwithstanding this structure. These can include, among other things, the apparatus being jarred during use or shipping, misalignment of the fiber array in the tuning fork assembly, misalignment of the predetermined initial firing setting of the laser beam, and potential manufacturing defects in the silicon cassette that contribute to slight misalignment. Yet a laser system ideally will not become unusable simply because the laser beam is unable initially to impinge directly upon each active treatment optical fiber in the fiber array due to misalignment. Rather, it is preferable to have the laser apparatus capable of discovering the exact location of the optical fiber array, and thus of each fiber in the array, even if the array is misaligned to some extent.
Manual adjustments of positioning mechanisms such as X-Y-Z tables, or analyses of backscattered light from the various proximal surfaces of an optical fiber cassette to determine the location of an optical fiberxe2x80x94i.e., retroreflectionxe2x80x94have previously been required at the outset of a procedure to ensure that a free laser beam of the kind disclosed in the ""700 application accurately impinges on a series of optical fibers in a linear array. Such adjustments were necessary so that once the laser was used for treatment, the laser could accurately and reproducibly locate each optical fiber without further major adjustments. However, it is preferable to eliminate most, if not all, of the required manual adjustments by having a laser system capable of verifying the location of the fiber array before treatment and adjusting itself accordingly, or of determining that the fiber array is unusable for whatever reason. The inventions disclosed herein enable alignment of a free beam of radiation with a fiber array notwithstanding slight misalignment of the array. The inventions disclosed in this patent application contribute to a laser apparatus"" capability to discover the position of one or more fibers in a fiber array, in order accurately and reproducibly to deliver a free radiation beam to that array.
Briefly and generally, an optical fiber cassette with multiple optical fibers is constructed with one or more, but fewer than all, optical fibers terminating short of the far distal ends of the remaining fibers. An apparatus including a light detecting means determines the actual position of the fiber cassette and/or verifies that the cassette is accurately positioned by detecting light transmitted through the shorter fiber(s) as a laser beam is horizontally and/or vertically scanned across the proximal fiber end(s). Positioning (or registration) fiber(s) may terminate inside an alignment block attached to the fiber cassette that facilitates delivery of the cassette to an accurate positioning means comprising two substantially parallel pins.
Additional objects, features and advantages of the various aspects of the present invention will be better understood from the following description of its preferred embodiments, which description should be taken in conjunction with the accompanying drawings.